The first commercial airlock will be added to the International Space Station in two years. NASA has accepted a proposal from NanoRacks, a company that already operates two research platforms in the US' National Laboratory in the ISS.

NASA hopes initiatives of this sort will move towards establishing an commercial sector in low-Earth orbit.

We want to utilize the space station to expose the commercial sector to new and novel uses of space, ultimately creating a new economy in low-Earth orbit for scientific research, technology development and human and cargo transportation. We hope this new airlock will allow a diverse community to experiment and develop opportunities in space for the commercial sector. - Sam Scimemi, NASA

NanoRacks will work with Boeing on the airlock. It's expected to launch in a resupply mission and be added to a port in the Tranquility module in 2019.